Fredrick carl trapp



(No ModeU P. C. TRAPP.

RBVOLVING CHAIR.

No. 597,866. Patented Jan. 25,1898.

UNITED Sterns Arent einen,

FREDRIOK CARL TRAPP, OF PORT WASHINGTON, WISCONSIN, ASSIGNOR TO CHARLES C. TRAPP, OF SAME PLAGE.

REVOL'VING CHAIR.

SPECIFICATION forming part of Letters Patent No. 597,866, vdated January 25, 1898.

Application filed April 12, 1897.

To @ZZ whom zit may concern,.-

Be it known that I, iinnmuor: CARL TRAPP, of Port Washington, in the county of Ozaukee and State of `Wisconsin, have invented a new and useful Improvement in Revolving Chairs, of which the following is a description, reference being had to the accompanying drawings, which are a part of this specification.

My invention consists in the means for supporting a chair-seat revolubly in such manner that the seat can be adj usted vertically and that when so adjusted the seat will revolve freely without running down under the load of and on the chair-seat when the chair is oscillated from side to sideand in improvements incidental to such a construction.

The invention consists of the mechanism, its parts and combinations of parts, as herein shown and described and claimed, or their equivalents. I

In the drawings, Figure l is an illustration, mostly in section, of my improved chair-iron. 2 is a top plan view of the nut turning on the screw-threaded post. Fig. 3 is a detail of the spindle-supporting device. Fig. i is a transverse section of the post, showing an oilduct therein.

In the drawings, A is the base of the chairiron, to which the legs are to be affixed, which base is provided with a central vertically-disposed smooth bore. A hollow cylindrical and eXteriorly-screW-threaded post B is fitted in the bore of the base A and is supported thereon, preferably by having the lower extremity of the post contracted, forming a shoulder at O,Which rests on the top ot the base A, the contracted or smaller portion D of the post fitting in the bore ot' the base A. The post B is provided with one or more longitudinal channels E E, and in one or both of these ahey or keys F may be inserted, wedging the post tightly in the base A.

A nut G tits and turns on the thread of the post B, and the nut is preferably provided with a radially-projecting web G', so constructed as practically to form a hand-wheel adapted to serve as a 'means for seizing and rotating it by hand. A movable platform or collar II, .having a vertical aperture corresponding in size with the bore of the post B, is provided with a depending leg I, fitted and Serial No. 631,744. (No model.)

adapted to slide vertically in one of the channels E in the post B. At and near its lower extremity this leg I is provided with a laterally-projecting lug or toot K, adapted to rest on the upper end of the nut G, while a neel; L of substantially the thickness of the depth of the channel E extends in the' channel through the nut, and a lug or toe M, projecting laterally from the extremity of the neck, takes under and bears loosely against the lower end of the nut G. By means of this construction the collar II is supported on the nut and is raised and lowered by rotating the nut on the thread of the post B, the leg` I being held to vertical movement with the nut by the toe M and the foot K, the nut rotating on the post freely about the neck L, which is wholly within the channel E.

I also show a second leg I', depending from the collar I-I and adapted to rest on the upper surface of the nut G, the leg I being located on the opposite side of the. post B from the leg I and being also :fitted and movable in a channel E in the post. This additional leg I' is only desirable where greater strength is required to support the collar I-I than would be furnished by the single leg I, and when this additional leg is not employed the corresponding channel E in the post B need not be provided.

A spindle O, having a smooth exterior cylindrical surface, is fitted and supported revolubly on the collar H and extends into the bore of the post B, whereby its upright position is maintained. The spindle O is intended and adapted to be Xed to the under side of a chair-seat, which is supported thereon.

To permit of a satisfactory lubrication of the bearing of the spindle O in the post B, I provide a spiral channel or duct P in the surface of the bore ot the post, which spiral channel extends from the top of the post downwardly nearly as far as the ordinary spindle extends therein, where the duct terminates in a horizontally-disposed annular channel or oil-duct P cut in the surface of the bore.

To prevent the accidental or undesired removal of the chair-seat and spindle O from the post B, a pin R is inserted in or through the spindle O just beneath the collar II, this pin being preferably removable. The pin is IOO so constructed and inserted in the spindle as to permit the free revolution thereof in the collar II and post B.

I am aware of the invention and application, Serial No. 624,363, filed February 20, 1897, by Charles C. Trapp and Frank Trapp, for a patent for improvement in revolving chairs, and

- I do not claim that invention or any features of it, but claim only the invention that is involved in my improved construction as differentiated from said invention of Charles C. Trapp and Frank Trapp.

That I Claim as my invention is 1. In a revolving chair, the combination, with a base and an exteriorly-sereW-threaded post iixed on the base, said post having a vertical bore and an exterior longitudinal channel, of a collar above the post provided with a leg slidable in the channel in the post, and a'nnt turning on the post over a part of the leg of the collar therein, the leg having a lug or foot resting on the nut.

2. In a revolving chair, the combination with a base and an exteriorly-sereW-threaded post xed on the base, said post having a vernut turning on the post over a part of the leg of the collar therein, a foot on the leg above the nut and a toe on the leg below the nut.

3. In a revolving chair, the combination With a ba'se and an eXteriorly-sereW-threaded post fixed on the base, said post having a vertieal bore and an exterior longitudinal channel, of a collar above the post, and provided with depending legs slidable in channels in the post, and a nut turning on the post over a portion of one of the legs, both legs being supported on the nut.

In testimony whereof I my signature in presence of two witnesses.

FREDRICK CARL TRAPP. Witnesses:

C. T. BENEDICT, ANNA vV. FAUsT. 

